Electrophysiology catheters are commonly-used for mapping electrical activity in the heart. Various electrode designs are known for different purposes. For example, catheters having basket-shaped electrode arrays are known and described, for example, in U.S. Pat. Nos. 5,772,590, 6,748,255 and 6,973,340, the entire disclosures of each of which are incorporated herein by reference.
Basket catheters typically have an elongated catheter body and a basket-shaped electrode assembly mounted at the distal end of the catheter body. The basket assembly has proximal and distal ends and comprises a plurality of spines connected at their proximal and distal ends. Each spine comprises at least one electrode. The basket assembly has an expanded arrangement wherein the spines bow radially outwardly and a collapsed arrangement wherein the spines are arranged generally along the axis of the catheter body.
It is desirable that a basket assembly be capable of detecting in as few beats as possible, including a single beat, as much of the electrical function of the region in which the electrode assembly is deployed, such as the left or right atrium. Conventional basket-shaped electrode assemblies are generally spherical or otherwise describe a smoothly rounded compact volume in which the spines, and correspondingly the electrodes, are constrained to the outer surface of the shape. However, the heart chamber or other region in which the catheter is deployed may not match the shape of the basket-shaped electrode assembly, resulting in a suboptimal degree of contact between one or more of the electrodes carried by the spines and the tissue being investigated.
Accordingly, it would be desirable to provide an EP mapping catheter that offers increased contact with an irregularly shaped heart chamber or other body cavity. As such, it would be desirable to provide such a catheter with spines having a greater degree of freedom than the spines of a conventional basket-shaped electrode assembly to allow them to more readily conform to surrounding walls of tissue. The techniques of this disclosure as described in the following materials satisfy these and other needs.